1. Technical Field
The present invention relates to plumbing set forth in subclass E03C of the International Patent Classification (IPC), and more particularly, to a drain valve device capable of eliminating drain odor, and blocking intrusion of pests, such as cockroaches and mosquitoes, and effective in removing trapped hair and residue.
2. Description of Related Art
Referring to FIG. 1, a conventional floor drain structure comprises a water-collecting recess 1 and a plate strainer 2. A plurality of perforations 3 is disposed across the surface of the plate strainer 2 and adapted to filter out leftovers, hair, and residue. Not only is the water-collecting recess 1 in direct communication with a drainpipe, but the perforations 3 of the plate strainer 2 are also open fully; hence, odor builds up in the drainpipe and seeps into the house through the perforations 3 readily. Furthermore, the end section of the drainpipe is exposed outdoors; as a result, pests, such as cockroaches and mosquitoes, are likely to intrude into the house and thereby cause diseases, such as Dengue fever, to the household. Hence, the aforesaid drawbacks of the conventional floor drain structure pose a threat to home hygiene and remain unsolved.
Various odor-proof floor drain structures developed by manufacturers are not free from drawbacks, namely not effective in filtration, not convenient to clean, and not durable, and thus the prior art still has room for improvement.